In connection with Compounds (I) (described afterward) in the present invention, it is known that compounds represented by the following formula ##STR3## in which R.sup.1a represents hydrogen, substituted or unsubstituted lower alkyl, or lower alkanoyl, R.sup.2a represents hydrogen, lower alkenyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted aralkyl, or a substituted or unsubstituted heterocyclic group, R.sup.3a represents a substituted or unsubstituted 5-membered heterocyclic group, X.sup.a represents O, S, S(O), S(O).sub.2, or NR.sup.4a (in, which R.sup.4a represents hydrogen, or substituted or unsubstituted lower alkyl, or R.sup.2a and NR.sup.4a are combined to form a substituted or unsubstituted 4 to 6-membered saturated heterocyclic group), and A.sup.a represents N or CR.sup.5a (in which R.sup.5a represents hydrogen, or substituted or unsubstituted lower alkyl), and compounds represented by the following formula ##STR4## in which R.sup.1b represents hydrogen, substituted or unsubstituted lower alkyl, or lower alkanoyl, R.sup.2b represents substituted or unsubstituted lower alkyl, lower alkenyl, lower alkynyl, substituted or unsubstituted phenyl, or a substituted or unsubstituted 5- or 6-membered heterocyclic group, and A.sup.b represents N or CR.sup.5b (in which R.sup.5b represents hydrogen, or substituted or unsubstituted lower alkyl), have an selective adenosine A.sub.2 antagonistic activity (Japanese Published Unexamined Patent Application No. 97855.93 and EP 515107A).
Further, in connection with Compounds (II) (described afterward), it is known that compounds represented by the following formula ##STR5## in which R.sup.6a represents substituted or unsubstituted phenyl, or a substituted or unsubstituted heterocyclic group, Y.sup.a represents O, S, or NR.sup.7a (in which R.sup.7a represents hydrogen, substituted or unsubstituted lower alkyl, lower alkenyl, lower alkynyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl), R.sup.8a represents hydrogen, substituted or unsubstituted lower alkyl, lower alkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl, and B.sup.a and the adjacent two carbon atoms are combined to form a substituted or unsubstituted, saturated or unsaturated, monocyclic or bicyclic, carbocyclic or heterocyclic group, have an adenosine A.sub.2 antagonistic activity and exhibits an antispasmic activity and a bronchodilating activity [Japanese Published Unexamined Patent Application Nos. 165386/86 and 135475/87, J. Med. Chem., 31, 1014 (1988)].